Correct but uneven performance between multiple cards purchased at the same time?!?

Map 1:

512KB Random Write: 15,448 MB / s Random Write 4KB (QD = 1): 1.279 MB / s [312.1 IOPS] Random Write 4KB (QD = 32): 1781 MB / s [434.8 IOPS]
Map 2:

512KB Random Write: 29,756 MB / s
4KB Random Write (QD = 1): 1,540 MB / s [376.1 IOPS]
4KB Random Write (QD = 32): 1867 MB / s [455.8 IOPS]

Another point, this card comes formated with exFAT (normal for an SDXC card), but with a size of 128KB blocks, this size is excessive and will lose a lot of space as to-and as we will add files (each file will use a rounded size 128KB higher even if the file is a single character), you better reformat the card with blocks of 32K it will lose less space.